Recyclable, thermally insulated plastic container

ABSTRACT

A two-piece thermoformed, thermally insulated container such as a hot drink cup comprising a tapered cup body with vertical ribs on the outer body surface thereof and a sleeve attached to the cup on and overlying the top surfaces of the ribs. This forms a series of parallel air gaps between the sleeve and the cup over substantial portion of the length thereof. The sleeve may be printed with appropriate logos or other indicia. The cup and sleeve are both preferably made of polypropylene so that they may be recycled as a unit.

FIELD OF THE INVENTION

The invention relates to recyclable, thermally insulated plastic containers of the type used to dispense or store food or drink products, and more particularly to a two-piece container comprising a vertically, externally ribbed inner cup and a flexible sleeve wrapped around the cup so as to span the ribs and create vertical air spaces for insulation. The sleeve may be printed and is preferably of the same material of the cup thereby to allow the entire cup to be recycled without separating the components.

BACKGROUND OF THE INVENTION

Restaurants, cafeterias and other food service facilities commonly use treated paper or Styrofoam cups to dispense coffee, cocoa, soup and other hot products. A number of devices have been developed to provide thermal insulation on the outside of such cups to prevent discomfort to a consumer when the cup is filled with, for example, hot coffee or soup. One popular device is a cardboard sleeve which one can telescopically slide onto a cup from the bottom to protect the consumer's fingers from heat. Other devices include formed plastics.

Problems associated with these devices include the fact that the cups and sleeves have to be manufactured, shipped and dispensed as separate units thus adding to costs. Secondly, they are sometimes made of different materials and, to the extent they are recycled, must typically be separated and placed in separate containers for collection by recyclers.

SUMMARY OF THE INVENTION

The present invention provides a unitary, thermally-insulated container such as a single-service drink cup, designed for use in the service of hot products such as coffee, tea, soup and cocoa. The entire container is made of a plastic material such as polypropylene and includes an inner cup portion formed with vertical ribs and intermediate recesses of the sidewall thereof. Overlying the outside surfaces of the ribs is a sleeve, preferably also of sheet polypropylene. The sleeve is secured to the cup with a butt seam adhesively overlying a rib surface so that the two elements are recycled as unit. Because the sleeve overlies the ribs of the cup, there are vertical air spaces between the ribs thereby to provide insulation that protects the user against discomfort, as the result of grasping a cup filled with a hot fluid.

In the illustrative embodiment shown in the drawings and described herein, the cup body is formed with a first smooth circumferential band near the top rim and a second smooth annular band immediately below the first band but of smaller diameter to form a step. The surface of the second, lower band extends downwardly in the form of circumferentially-spaced ribs with recesses between them. The surfaces of the recesses extend downwardly into a smooth bottom band. The wraparound sleeve extends substantially from the step to the bottoms of the ribs such that the vertical air spaces are open at the bottom and closed at the tops. The entire container may be tapered and the top band may be reversely-tapered to prevent the containers from completely telescoping when stacked.

While the invention will be described herein with respect to a tapered drink cup, it may be configured for other uses and in various sizes. Other advantages, features and characteristics of the present invention will become more apparent upon consideration of the following detailed description and the appended claims with reference to the accompanying drawings, the latter being briefly described hereinafter.

BRIEF SUMMARY OF THE DRAWINGS

The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views and wherein:

FIG. 1 shows a single-service, thermoformed, thermally insulated drink cup constructed in accordance with the invention;

FIG. 2 shows the cup of FIG. 1 partially exploded to indicate the nature of the two pieces thereof;

FIG. 3 is a sectional view of the cup with the outer sleeve applied thereto;

FIG. 4 is a detail of the cup and sleeve combination along a section line which runs through a recess thereby showing the air gap between the cup and the outer protective sleeve; and

FIG. 5 is another sectional view of the cup through a rib line where the outer sleeve is bonded to the tapered cup body.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENT

Referring to the figures, there is shown an all-plastic, thermally insulated single-service drink cup-type container 10 comprising an open top tapered cup body 12 having a circular rim 14 and attached around the outer surface thereof, a sheet plastic sleeve 16, the cup 12 and the sleeve 16 both preferably being formed of polypropylene. The cup is thermoformed using complemental male and female dies and the sheet sleeve 16 is extruded and die cut.

Referring to FIGS. 2 and 3, the inner, primary cup portion of the container 10 is shown to have an open top with a rim 14 of a first diameter. Immediately and contiguously below the rim is a smooth, continuous circumferential band 18 with a reverse taper, the bottom diameter of which is slightly larger than the inner diameter of the rim 14. The reverse taper prevents telescoping of stacked containers when shipped or stored in multiples. Below the band 18 is a second band 20 of a third lesser diameter than that of the band 18 to form a step 34. Band 20 is the beginning or top of the tapered portion of the cup body and extends downwardly in the form of multiple, circumferentially spaced apart, generally parallel ribs 26 with flat outer surfaces.

Between the ribs 26, the cup has thermoformed therein parallel, vertical recesses 28 with arched tops 30 which, as shown in FIG. 1, print through to the interior of the cup body 12. The recesses 28 flow downwardly into an integral, smooth bottom band 22 with a floor 24. The floor 24 is preferably slightly recessed for stiffness. The proportions of the cup are such as to have a height-to-width ratio of approximately 3:2 and a capacity of between 4 and 32 fluid ounces, albeit somewhat smaller and larger cups may also use the invention concept described herein. In a 12 oz. size, the width of the recesses 28 is about 0.375 inches at the top; the width of the ribs 26 is about 0.0625 inch and the depth of the recesses 28 is about 0.020 inches. Therefore the ratio of recess width to rib width is about 6:1 but this is an approximate figure as a range of about 10:1 to 2:1 will work. The thermoformed cup is 15-20 mil polypropylene and is thermoformed from sheet material using conventional thermoforming techniques including a vacuum-assisted platens and both female and male tooling. The dimensions described above are by way of example. Moreover, the body may be wider, straight-sided, and less tall to dispense, for example, soup or pasta. If the cup is larger, the circumferential spacing between ribs 26 does not increase in proportion because it is undesirable to have too much give in the sleeve material between ribs 26. Thicker sleeve material can alleviate this effect to some degree but thicker material adds undesirable weight.

As shown in FIGS. 4 and 5, a sheet-like polypropylene sleeve 16 is conformingly wrapped around the cup body fully between step 34 and essentially at the bottoms of the ribs 26. Sleeve 16 is preferably adheringly bonded either with adhesive or thermal fusing to the top surfaces of the ribs 26 in several places and the edges of the sleeve 16 are joined with a butt seam overlying a flat rib surface. The bonding of the sleeve to the ribs may be intermittent, spotty or uniform, the object being to join the sleeve 16 to the cup body so they become a single unit. This forms gaps 32 as shown in FIG. 4 between the sleeve 16 and the outer surfaces of the recesses 28 which gaps are closed at the top but open at the bottom to provide insulating air spaces. The outer sleeve 16 is made in a 0.015″ thickness and is pliable enough to be readily wrapped around the cup 12 after being die-cut to fit the appropriate size and bonded in place with a vertical seam. The cup material may be from about 0.010 to 0.030 inches thick and the sleeve material may be from 0.05 to 0.030 in. thick.

A conventional thermoformed lid (not shown) or closure may be snap-fit onto the rim 14, said closure typically but optionally being provided with drink-through features, such as simple apertures or fold-back/lock-back tabs. The topography of the lid may vary widely between low profile flat tops and crowned “Cappuccino” lids with high tops. The reverse taper-to-band 18 prevents full telescoping when the containers are stacked.

While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law. 

What is claimed is:
 1. A recyclable, thermally insulated container comprising: an open top plastic cup having a generally cylindrical sidewall and an integral floor; said cup having a circular top rim of a first diameter and, immediately below but contiguous to said rim, a smooth annular band, said cup sidewall below said band being generally of a diameter less than the diameter of the band to form a step, said sidewall having formed therein a plurality of parallel vertical outwardly projecting ribs defining therebetween recesses having tops spaced below said step and separated from one another by said ribs; all of said ribs extending on said sidewall to a circumferential location near but spaced upwardly from said floor; and an outer label layer overlying said ribs, the vertical length of said label layer being such as to extend from said step to the lower ends of said ribs so as to create air spaces between said label layer and said recesses, which air spaces are open at the bottoms thereof.
 2. The recyclable, thermally insulated, container defined in claim 1 wherein said cup and label layer are made of the same plastic material so as to be recyclable as a unit.
 3. The recyclable, thermally insulated container defined in claim 2 wherein the material is polypropylene.
 4. The recyclable, thermally insulated container defined in claim 1 wherein the label layer abuts said step.
 5. The recyclable, thermally insulated container as defined in claim 1 wherein the label layer has a butt seam overlying a rib.
 6. The recyclable, thermally insulated container as defined in claim 1 wherein the smooth annular band has a reverse taper to prevent full telescoping of said containers when stacked.
 7. The recyclable, thermally insulated container as defined in claim 1 wherein the container has a fill capacity of between 4 and 32 fluid ounces.
 8. The recyclable, thermally insulated container as defined in claim 1 wherein the material thickness of the label layer is between about 0.005 and 0.030 inches.
 9. The container defined in claim 1 wherein the ratio of the width of said recesses to the width of said ribs is about 6:1. 